Bi-fold frames for supporting futons are well known in the prior art. These frames include two sections which generally are movable relative to each other, between a "couch" orientation, in which the sections are disposed to form a seat and backrest, and a "bed" orientation, wherein futon-supporting surfaces of the two sections generally lie in the same plane.
In the bed orientation, the futon functions as a mattress, with the distance between the front edge of the seat section and the rear edge of the backrest section constituting the width of the bed, and with the length of the frame, from one side edge to the other side edge, constituting the length of the bed.
To maintain the sections of the bi-fold units in the couch orientation to provide a seat and backrest for supporting a futon, a locking arrangement may be provided between the pivotal sections. In one such prior art construction, pivoting locking blocks are rotatably secured to transversely-spaced side frame members of the backrest section. These blocks are designed to engage the upper surface of the section forming the seat, to prevent inadvertent movement of the backrest section relative to the seat section when the frame is being employed in its "couch" orientation. Although this pivoting block arrangement may provide a satisfactory locking force to maintain the bi-fold sections in the "couch" orientation, it is quite cumbersome to operate the blocks for the purpose of converting the frame to its "bed" orientation, and then back to its couch orientation. Specifically, in order to make these conversions it is necessary for the person to physically bend over and rotate the block on each side frame of the backrest section. This generally requires the user to move from one side of the frame to the other, and in some cases, may even require two individuals to simultaneously move the pair of pivoting blocks. Moreover, since the pivoting blocks generally are adjacent the lower end of the backrest section (in order to properly engage the seat section) the person operating the frame often needs to bend into an uncomfortable position to operate the pivoting blocks.
In another arrangement, wooden dowel pins are provided to fit into aligned holes of the seat section and backrest section, at each side of the construction, when the seat and backrest sections are disposed in the "couch" orientation. In this orientation, the openings are aligned to receive the dowel pins. To convert this latter frame construction into a bed, a person first removes the dowel pin from one side of the construction, and then from the other side. Moreover, it is quite inconvenient and cumbersome to again try to reposition and lock the frame members in the "couch" orientation.
In my prior U.S. Pat. No. 5,170,519, the entire disclosure of which is incorporated by reference herein, other prior art convertible bi-fold and tri-fold frame constructions are disclosed. In both of these latter constructions, the frame is movable from a first to at least a second orientation. The frame has at least two sections pivotally connected together and movable relative to each other. One of the two sections includes a frame member having one end closely adjacent to, and overlapping an end of a frame member of the other of the two sections. A unique hinge and stop arrangement is provided to permit the relative rotational movement between the two sections to convert the frame between the first and second orientations, and also to lock the two sections against relative rotational movement in one of the first and second orientations. The hinge and stop arrangement includes an elongate slot in one of the overlapping ends and a hinge pin connected to the other of the overlapping ends. The hinge pin is rotatably retained within the slot to provide a pivotal connection between the first and second sections. Cooperating stop members are provided on the adjacent overlapping ends to engage each other when the hinge pin is in a first location within the elongate slot to maintain the frame in the first orientation, and for disengaging from each other when the hinge pin is in a second position within the elongate slot to permit the frame to assume the second orientation.
One fundamental problem of the prior art "L-frames" is that if they have large leg members to provide a bed frame which places the mattress a suitable height above the floor, then there is much wasted space between the rear of the backrest portion of the L-frame when the backrest portion is placed adjacent the wall of a room, since the leg members associated with the backrest portion are typically located at the rear of the backrest portion when not in use. The wasted space behind the L-frame, when the unit is in the couch orientation, is extremely undesirable, especially since L-frame units are typically utilized in small rooms or apartments. Prior art constructions which have attempted to minimize this wasted space by decreasing the width of the leg members also produce an undesirable L-frame. By decreasing the width of the legs, when the L-frame is placed in the bed orientation, the frame and mattress lie too low to the ground, which is not as aesthetically pleasing to many individuals. Additionally, a low bed frame is also undesirable since it is very difficult for many individuals to get into and out of the bed.
In view of the problems associated with prior art frames, a need exits for an economical and simple-to-operate bi-fold unit which can easily be converted between a "couch" and a "bed" frame orientation, without wasting space adjacent the unit, while providing a bed height which is not unacceptably low to the ground,
Two prior art convertible furniture constructions utilizing spaced apart swing arms are disclosed in U.S. Pat. Nos. 2,751,605 and 2,700,164. However, these constructions do not provide the advantages and benefits of the construction of the present invention.
Other prior art convertible furniture constructions are also shown in U.S. Pat. Nos. 4,875,244; 4,829,611; 4,692,952; 4,642,823; 4,538,308 and 2,294,475.
However, none of the prior art constructions known to the inventor solve the heretofore mentioned problems associated with frame constructions in the simple and reliable manner accomplished by the present invention.